<html>
<head>
    <title>Librera</title>
    <style>
.center {
  display: block;
  margin-left: auto;
  margin-right: auto;

  height: 100%;
}








    </style>

    <script type="text/javascript">

function point_it(event){
    w = document.getElementById("myimg").width;
    h = document.getElementById("myimg").height;
	x = event.offsetX?(event.offsetX):event.pageX-document.getElementById("myimg").offsetLeft;
	y = event.offsetY?(event.offsetY):event.pageY-document.getElementById("myimg").offsetTop;
	//alert(""+pos_x+"x"+pos_y+"w"+w+"h"+h);
	//alert(""+x/w + ":"+y/h);
	 document.getElementById("xy").value = "" + x/w+"_"+y/h;
	 document.getElementById("form").submit();
	 // alert(form.action);
}


    </script>

</head>
<body>

<form id="form" method="get">
    <img id='myimg' class="center" src="download.png" onclick="point_it(event)"/>
    <input type="input" id="xy" name="xy" style="display:none">

</form>


</body>
</html>